Inconsistent formatting with --format=pep8

[blueyed]

I have noticed that the formatting for "--format pep8" is inconsistent, because
it will not have a type field (E) and number:

Given t.py:

 = meh

% pylama -l  mccabe,pep8,pyflakes,pep257 --format=pep8 t.py
t.py:1:2: E111 indentation is not a multiple of four [pep8]
t.py:1:2: E113 unexpected indentation [pep8]
t.py:1:1: unexpected indent [pyflakes]

This makes it more difficult to parse (e.g. using Vim's errorformat).

With --format=pylint:

% pylama -l  mccabe,pep8,pyflakes,pep257 --format=pylint t.py
t.py:1: [D] D100: Missing docstring in public module [pep257]
t.py:1: [E] Invalid syntax: = meh [mccabe]
t.py:1: [E] unexpected indent [pyflakes]

(The same file with the "pylint" format gets different errors, which appears to
be a separate issue?! pep257 and mccabe is used here, but pep8 is not.
That happens when using pyflakes, which throws a SyntaxError from

pylama/pylama/lint/pylama_pyflakes.py

Line 41 in e9e926f

tree = compile(code, path, "exec", _ast.PyCF_ONLY_AST)

, which causes pylama to abort. It does not depend on the format, but in which order linters get run)